Avaya G430 Manual page 435

Note:
There may be cases in which the GRE tunnel is not used for routing. In such cases, it may
not be necessary to assign an IP address to the tunnel.
The main application for GRE tunneling is to allow packets that use protocols not supported
on the Internet, or packets that use private IP addresses that cannot be routed on the Internet,
to travel across the Internet. The following are examples of situations in which this can be
useful:
• Providing multiprotocol local networks over a single-protocol backbone
• Providing workarounds for networks containing protocols that have limited hop counts,
such as AppleTalk
• Connecting discontinuous subnetworks
• Enabling virtual private networks (VPNs) over a WAN
You can also configure a GRE tunnel to serve as a backup interface. For information on
configuring backup interfaces, see
For an example of a GRE tunneling application, see
page 441.
Related topics:
Packet routing to a GRE tunnel
Prevention of nested tunneling in GRE tunnels
Optional GRE tunnel features
Setting up a GRE tunnel
GRE tunnel application example
Summary of GRE tunneling commands
Packet routing to a GRE tunnel
Packets can be routed to a GRE tunnel in the following ways:
• The Tunnel interface is configured as the next hop in a static route. See
configuration
• The packet is routed to the Tunnel interface dynamically by a routing protocol (RIP or
OSPF)
• The packet is routed to the Tunnel interface via policy-based routing. See
routing
Administering Avaya G430 Branch Gateway
on page 435
on page 438
on page 440
on page 430.
on page 587.
Backup interfaces on page 256.
GRE tunnel application example
on page 436
on page 441
on page 443
The router
on
Routing table
Policy-based
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